Dual Layer X-ray photoelectron spectroscopy model to simultaneously determine a PFPE/A20H lubricant mixture and carbon-Layer thicknesses on hard-disk magnetic media

New blends of complex lubricants have recently been introduced to help meet the increasing tribological demands being placed on the head-disk interface in hard-disk drives. A20H (Moresco), a hybrid molecule consisting of a perfluoropolyether (PFPE) lubricant (Z-Dol) and cyclic phosphazene (X1P), is one such lubricant used in combination with a simple PFPE (e.g., Z-Dol). This paper describes an X-ray photoelectron spectroscopy (XPS) method to simultaneously measure the thickness of each lubricant component, as well as the carbon layer thickness, via reference to the magnetic layer.